PPSSPP is the first PSP emulator for Android (and other mobile platforms), that runs considerably faster than any other PSP emulator on Windows, Linux and MacOSX. PPSSPP can run your PSP games in full HD resolution, save and restore game states at anytime and allows you to continue where you left off by transferring saves from your real PSP. It also lets you upscale textures by cranking up the anisotropic filtering and texture scaling which would otherwise appear to be too blurry as they were made for the small screen of the original PSP.
Ridge Racer 2 running on PPSSPP with up-scaled textures
PPSSPP v1.4 includes the following changes:
Support D3D11 (performs better than OpenGL or D3D9 on most hardware)
Hardware spline/bezier tesselation in OpenGL, D3D11 and Vulkan (…)
Post-processing shaders in D3D11
Prescale UV setting removed, now the default (improves perf) (#9176)
High DPI display fixes
Various fixes for UMD switching for multi-UMD games (#9245, #9256)
New audio setting to improve compatibility with Bluetooth headsets
Various desktop gamepad compatibility fixes
Workaround for mipmap issue, fixing fonts in Tactics Ogre Japanese
Assorted minor compatibility fixes, code cleanup and performance improvements
You can grab PPSSPP for your preferred OS at their official site. If you’re an android user and you want to support the development of PPSSPP, you should consider buying the Gold version of PPSSPP for Android :).